docs: def write_to_stdin(self, message):
          """
          Write provided text to container's standard input. In order to make this function work, there needs to be several conditions met:
           * the container needs to be running
           * the container needs to have stdin open
           * the container has to be created using method `run_via_binary_in_foreground`
  
          For more info see documentation in run_via_binary_in_foreground()
  
          :param message: str or bytes, text to be written to container standard input
          """
          if not self.is_running():
              raise ConuException(
                  "Container must be running")
          if not self.popen_instance:
              raise ConuException(
                  "This container doesn't seem to be created using method `run_via_binary_in_foreground`.")
          if not self.popen_instance.stdin:
              raise ConuException(
                  "Container should be run with stdin redirection.")
  
          if not isinstance(message, bytes):
              if isinstance(message, str):
                  message = message.encode()
              else:
                  raise ConuException(
                      "Message should be an instance of str or bytes")
          try:
              self.popen_instance.stdin.write(message)
              self.popen_instance.stdin.flush()
          except subprocess.CalledProcessError as e:
              raise ConuException(e)